This application claims the priority of Korean Patent Application No. 2003-20734, filed on Apr. 2, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a method of producing 1,2-propanediol using Klebsiela pneumoniae. 
2. Description of the Related Art
1,2-propanediol is a very useful intermediate used in the production of optically active compounds including medicines, agricultural chemicals, antifreezes, and physiologically active agents.
According to a known chemically synthetic pathway for the production of 1,2-propandiol, 1,2-propandiol can be produced by the hydrogenation of propylene oxide derived from propylene. When producing 1,2-propandiol through this chemically synthetic pathway, excess water is necessary to suppress the production of polyglycol. In addition, the production of propylene oxide, which is involved in the production of 1,2-propandiol, requires costly chemical catalysts and leads to a large amount of byproducts, such as chlorohydrine and chroline, causing environmental contamination.
In a known biological method of producing 1,2-propandiol, L-rhamnose and L-fucose are utilized to produce by using E. coli and other microorganisms. However, L-rhamnose and L-fucose are very expensive and using these materials is uneconomical. Cameron et al. discloses a method of producing 1,2-propandiol from glucose using Thermoanaerobacterium thermosaccharolyticum HG-8 (ATCC 31960) (Biotechnol. Prog. 2001, Vol. 17, pp. 52˜56). U.S. Pat. No. 6,303,352 issued to Cameron et al. discloses a method of producing 1,2-propandiol from glucose using recombinant E. coli. 
However, all of the above-listed conventional methods utilize strains excluding Klebsiella pneumoniae. It is known that, when Klebsiella pneumoniae is incubated in a medium containing 6-deoxyhexose, such as rhamnose and fucose, in anaerobic conditions, the yield of 1,2-propandiol increases. It is also known that 1,2-propanediol can be produced from glucose using Klebsiella pneumoniae in both aerobic and anaerobic conditions. However, the yield of 1,2-propandiol from glucose is too low for commercialization (Juan Aguilar et al., J. Bact. January 1985, 435˜437).
There has been intensive research into a highly efficient method of producing 1,2-propandiol from a non-sugar carbon source, not expensive sugar carbon sources, such as 6-deoxyhexose, including rhamnose and fucose, using Klebsiella pneumoniae. As a result, the inventors of the present invention found that 1,2-propandiol can be produced with a high yield when Klebsiella pneumoniae is incubated in a medium containing a large amount of a common sugar carbon source, such as glucose, in aerobic conditions.